To provide an environmental adaptation type emulsion fuel which can be treated and used similarly as an ordinary fuel oil, and holds a highly good emulsion state over a long period.

This environmental adaptation type emulsion fuel is obtained by stirring and mixing a mixture liquid comprising ≥50 vol.% of a fuel oil and ≤50 vol.% of an emulsifier aqueous solution, while giving ultrasonic waves, and an environmental adaptation type emulsion fuel production installation comprises a mixing container 3 equipped with an ultrasonic wave-generating means 1 and a stirring means 2, and a water tank 4, a fuel oil tank 5, an emulsifier tank 6 and an environmental adaptation type emulsion fuel tank 7 which are connected to the mixing container 3.